This disclosure is directed to a process for improving octane boosters for gasoline, the improved boosters, and gasolines containing the boosters.
Commercial gasoline, which is fuel for internal combustion engines, is a refined petroleum product that is typically a mixture of hydrocarbons (base gasoline), additives, and blending agents. Additives and blending agents are added to the base gasoline to enhance the performance and the stability of gasoline, and can include anti-knock agents, anti-oxidants, metal deactivators, lead scavengers, anti-rust agents, anti-icing agents, upper-cylinder lubricants, detergents, and dyes.
When used in high compression internal combustion engines, gasoline has the tendency to “knock.” Knocking occurs when combustion of the air/fuel mixture in the cylinder does not start off correctly in response to ignition because one or more pockets of air/fuel mixture pre-ignite outside the envelope of the normal combustion front. Anti-knocking agents, also known as octane boosters, reduce the engine knocking phenomenon, and increase the octane rating of the gasoline. Prior octane boosters such as tetraethyl lead and methylcyclopentadienyl manganese tricarbonyl (MMT) have been or are being phased out for environmental, health, or other reasons.
Preferred compounds in present use for formulating octane boosters include C4 oxygenate compounds such as methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and n-butanol and its isomers. However, the production and storage of the large quantities of these materials at oil refineries can be costly. In addition, limitations on the use of high concentrations of additives by regulatory mandate increase the difficulty and expense of refining operations that produce high-octane fuels.
In view of the foregoing, there remains a need to provide cost-effective methods for producing octane-boosting compositions, including processes for modifying or improving the properties of existing octane boosters and compositions that are made by the processes.